Hair care compositions have traditionally been sold as liquid products. These liquid hair care products typically comprise a substantial amount of water in the formula. In addition to being liquids, many of the hair care products contain conditioning agents to provide one or more consumer recognized benefits relating to shine, softness, combability, antistatic properties, wet-handling, and manageability. One of the most effective classes of hair conditioning agents are cationic surfactant conditioners which are prevalent within a wide variety of retail hair conditioner products.
Cationic surfactant conditioners can be difficult to formulate within liquid conditioning compositions due to the strong interactions that they can have with other ingredients. While such negative interactions are widely appreciated in compositions comprising anionic ingredients (e.g., anionic surfactants, anionic polymers etc.), the incorporation of cationic surfactant conditioners is also known to present formulation challenges in combinations with other ingredients, especially non-ionic fatty alcohol conditioners which are typically employed within hair conditioning products. In particular, the cationic surfactant conditioner must synergize with the fatty alcohols (and other co-surfactants) to produce an optimum lamellar gel network structure that delivers consumer acceptable product rheology and is shelf stable. The lamellar gel network must also deliver sufficient deposition of the cationic surfactant conditioner to deliver the intended primary conditioning benefit to the hair. Additionally, the degree gel network formation is strongly tied to the level of the cationic surfactant conditioner within the composition and in particular driven by the ratio of the cationic surfactant conditioner to the fatty alcohol. Moreover, the deposition of the cationic surfactant conditioner and the resulting degree of hair conditioning delivered is strongly driven by the level of the cationic surfactant conditioner within the lamellar gel network composition.
Hence, a trichotomy presently exists during the formulation of liquid hair conditioners comprising cationic surfactant conditioners toward achieving the simultaneous benefits of improved hair conditioning, consumer acceptable rheology, and product shelf stability. All three of these consumer objectives are directly and simultaneously driven by the level of the cationic surfactant conditioner within the composition (and it's ratios to other components) and the optimum levels required to deliver one objective may differ from the optimum levels required to deliver one or both of the other objectives. Moreover, this problem is compounded by the fact that there exist multiple consumer segments, each requiring different levels of hair conditioning and correspondingly different levels of cationic surfactant conditioner. This results in time consuming iterative and highly resource intensive formulation efforts.
Therefore, it is an object of the invention to provide a hair care product comprising cationic surfactant conditioners that offers greater formulation ease and flexibility. In particular, it is an object of the invention to provide a hair care product incorporating a cationic surfactant conditioner in such a way that the level of the cationic surfactant conditioner drives primarily or singly the original desired hair conditioning performance benefit and does not simultaneously drive other competing product benefits such as product rheology/appearance or product shelf stability.
Additionally, it is an object of the present invention to provide a method for processing a porous dissolvable solid substrate comprising a cationic surfactant conditioner, whereby said process allows for late stage differentiation. The cationic surfactant conditioner active can be added and modified without changing the basic formula of the hair conditioning composition. It is further an object of the present invention to provide a porous dissolvable solid substrate with a cationic surfactant conditioner in the form of a unit dose hair care product.
Additionally, it is an object of the present invention to provide a porous dissolvable solid substrate that can be conveniently and quickly dissolved in the palm of the consumer's hand to constitute a liquid hair care composition. Additionally, it is an object of the present invention to provide a porous dissolvable solid substrate that contains a cationic conditioner active and additional actives.